1. Field of the Invention
The present invention is directed to flat panel displays and, in particular, to flat panel displays having improved low reflectivity.
2. Discussion of Related Art
A well-known problem associated with the viewing of an image through a sheet of glass or other light-transmissive or transparent material is that reflections of light or images originating on the viewing side of the material sheet can easily impede or interfere with or, in extreme cases, virtually prevent the successful viewing of the subject matter intended or desired to be observed through the transparent material sheet. This problem is particularly significant when viewing an image presented on an electronic screen display, such as a liquid crystal (LC) or plasma or other type of flat panel display. As such flat panel displays have become increasingly ubiquitous in devices and environments of all variety and in widely diverse applications, the need to minimize interference from reflections in the viewing of displayed images is more important than ever. Indeed, in some uses of flat panel displays—such for example to display flight data and situational information to the cockpit flight crew of an aircraft in flight—the need to effectively eliminate reflections that can distract the viewer or, even worse, impede or interfere with one's ability to readily perceive displayed data and images can assume a life-threatening urgency.
One long-known way of reducing the apparent reflectivity of a glass sheet is to “frost” the viewing surface—i.e. the “exterior” surface of the sheet which an observer directly views to see, through the sheet, an image that originates on or proximate the opposite “interior” surface of the glass sheet—so that the exterior surface carries a multiplicity of tiny, smoothly-contoured bumps or mounds. Such so-called frosted glass does not itself actually reduce the amount of reflection from the glass, but rather diffuses the reflections. Since the eye most readily perceives the sharp boundaries of contrast that are inherent in a clearly defined image, the resulting diffusion softens the reflected image and thereby creates for the viewer a perception of reduced reflectivity; this is because the “background” image (i.e. that which is viewed through the glass sheet) is visibly sharper than the “foreground” (i.e. reflected) image that has been diffused or softened by the contoured surface bumps on the glass sheet's exterior surface.
Also known for reducing reflections from the viewing surface of a glass or other transparent material sheet are anti-reflective coatings, such as high efficiency anti-reflective (HEA) coatings. HEA coatings are available in a wide variety of forms for application to the surfaces of glass sheets and the like, and have also been applied to glass sheets having a frosted surface to further enhance the viewing of images through the glass while minimizing the actual and perceived effects of reflected images.